Photoelectric generator



Filed May 1, 1929l .NvENToR Wfl/.Tar scf/a :ff/(rf BY www" ATTORN 'Patented May 12, 1936 PATENT ori-ice 2,040,632 PHOTOELECTRIC GENERATOR Walter Schottky, Berlin-Charlottenburg,

Ger-

many, assignor to Siemens & Halske, Aktiengesellschaft, Siemensstadt,

near Berlin, Germany, a corporation of Germany Application 'May 1, 1929, Serial No. 359,704 In Germany May 2, 1928 3 Claims. (Cl. 13G-89) My present invention relates to a light-sensitive device adapted to transform variations in light intensity into variations of an electric current.. It has been proposed hitherto to construct 5 photoelectric generators comprising a layer of cuprous oxide upon copper, this oxide layer having a rectifying effect in connection with the copper, a light-pervious electrode being arranged on the free or exposed surface of the cuprous oxide layer. I'he light passes through this electrode and through the cuprous oxide layer and impinges upon the surface at which the copper is in contact with the cuprous oxide, a photoelectric current being thus produced. This device of the prior art suffers from the very serious drawback that the cuprous oxide layer absorbs light very strongly, and that in a selective manner with respect to different colors, so that with light of a given intensity the photoelectric current eiect obtainable theoretically is very much impaired in practice.

According to my present invention, the metal or electrode which together with the layer of cuprous oxide or jof other semi-conductor prolight. I thus secure the result that the light passing through'such electrode will reach practically undiminished the contact surface between the said metal and the said semi-conductor layer; the

30 current produced by phctoelectric action will therefore be relatively large.

The layer of semi-conductor may bea layer of cuprous oxide which may be produced upon a copper base or electrode. In this case the copper 35' should be readily pervious to light, that is, it should be produced, by any well known or apf proved method, of such thinness that it will be of glass-clear transparency.

40 Reference is to be had to the accompanying drawing in which the ligure is a sectional view of a photoelectric cell embodying my invention.

For the sake of greater-clearness, the thicknesses of the several elements of the cell have been exaggerated in the drawing.

45 The photoelectric cell, adapted to receive light duces the rectifying eiect, is made pervious to from a light source 4 from the left as indicated by the arrows, comprises a metallic conductive electrode 1, of copper, for example, and prefer ably in the form of a thin metal i'oil, which is readily pervious to light, and preferably of glass- 5 clear transparency.

On this electrode 1 there is applied or produced, for example, a layer 2' of cuprous oxide, so that this semi-conductive layer forms with thev electrode 1 a rectifying connection. l0

The electrode 1 preferably is made with a reenforced edge. The light from the light source l passes through the electrode 1 and impinges in practically undiminished force on the contact surface between the electrode and the cuprous 0 oxide layer. A metal conductive electrode 3' is v provided on the other side of the semi-conductor 2.

The light-pervious metallic conductive electrode 1 may be provided with grid-like reenforcing ribs 8, whichat the same time cause better conduction of the current lfrom the thin metallic electrode 1. These grid-like reenforcing ribs 8 may be integral with the thin metallic electrode 1.

Iclaim:

l. A photo-electric generator comprising two metallic conductive electrodes and a semi-conductor layer located between them, said semiconductor layer being of cuprous oxide, the electrode on the light receiving side of said photoelectric generator being of copper and in intimate contact with substantially all oi' one surface of the semi-conductor and producing a rectifying effect therewith, said electrode being of such thinness as to be pervious to light.

2. A photo-electric generator as claimed in claim 1 in which the light pervious electrode is reenforced by ribs.

3. A photo-electric generator as claimed in claim 1 in which the light pervious electrode is reenforced by grid-like ribs integral with said electrode.

WALTER SCHO'ITKY.' 45 

